i don't think that the flash should be too bad. if you look at the link of the pics taken in KuchDaddy's thread, it doesnt look too bad. i like the shimmer effect personally. I placed the test panels behind the tank and the blue is a bit darker then the blue cellophane, and looks similar, but i attribute that to the fact that its not actually painted on. It should look ten times better i think.
Alot of people i have asked so far say they like the cobalt blue as well, woot.